Recently, a device described in International Application Publication No. WO/2004/086944 has been proposed as a medical treatment device for a patent foramen ovale (hereinafter, referred to as PFO: Patent Foramen ovale) which is a cardiogenic factor of a stroke and a hemi headache.
This PFO closing device is a device in which an apparatus is inserted into the foramen ovale from the right atrium toward the left atrium, a foramen ovale valve is pulled to the foramen ovale to close it, and the biological tissue is fused by applying electric energy.
However, the foramen ovale, the foramen ovale valve and the atrial septum secundum are different not only with respect to size, but also with respect to a state of thickness, shape or the like. Depending on the person and according to other circumstances, the size or the like of the apparatus may be restricted a lot. Also, even on an occasion when the procedure is performed, there is a fear that it becomes difficult to pull various forms of foramen ovale valves to the foramen ovale in a desired and reliable manner.
Consequently, the applicant here previously proposed a PFO closing device in which the foramen ovale valve and the atrial septum secundum are sandwiched by a pair of electrodes, and the biological tissue is fused reliably by applying electric energy from both the electrodes. This PFO closing device is shown in International Application Publication No. WO/2007/100067.
This device uses clamping means in which one side thereof is made of a sticking member composed of a needle electrode and the other side thereof is made of a sandwiching member for sandwiching the foramen ovale valve and the atrial septum secundum with respect to the sticking member. The sticking member is stuck into the foramen ovale valve and thereafter, the foramen ovale valve and the atrial septum secundum are sandwiched with respect to the sandwich member which is the other electrode, electrical energy is applied to the biological tissue, and fusion is carried out.
This device can be used also in case of closing defects such as a congenital atrial septum secundum defect (ASD), a PFO, a ventricular septal defect (VSD) and a patent ductus arteriosus (PDA). It is also a device having high general versatility and in particular, foreign substances are not indwelled in the body, the constitution becomes simple, also the procedure becomes easy and the foramen ovale valve and the atrial septum secundum can be fused reliably.
However, to steer this device, a cable for supplying electric energy and a fine and long-line shaped member for steering the clamping means remotely are provided on the steering unit, so that various steering means exist in the steering unit and there is a fear of miss-steering. In particular, in case of sandwiching a tissue and thereafter fusing it by applying electric energy, when the electric energy is applied, there is a fear that electric current flows not only in the desired region but also in an unnecessary region. There is also a fear that a thrombus will be attached depending on the temperature-rise of the sticking member or the like. When the thrombus is exfoliated from the sticking member or the like and reaches a peripheral vessel of the brain from the left atrium, a cerebral infarction or the like would occur, so that the attachment of the thrombus should be prevented as much as possible.
Also, in case of sandwiching a biological tissue by clamping means, the surgery operator sticks a sticking member to the foramen ovale valve while maintaining a state in which the foramen ovale valve which has a thin-film shape and is easily deformed is held by a sandwiching member. Specifically, for example, in a state in which the sandwiching member is held by the left hand so as not to be displaced, the sticking member is steered by the right hand and the sticking is executed, but when the holding by the left hand is loosened, the sticking cannot be executed and therefore, there is also such a practical problem that the operator must concentrate on both the right and left hands.